The present invention relates generally to semiconductor technology. More particularly, embodiments of the present invention provide a semiconductor device having improved core and inputs/outputs reliability and a method for manufacturing the semiconductor device.
Increasing circuit density has not only improved the complexity and performance of integrated circuit devices but also has provided lower cost parts to consumers. With decreasing feature sizes and increasing current density in semiconductor devices, in order to reduce the equivalent oxide thickness of the layer (EOT), high-k dielectric layer after the metal gate (high-K/metal gate all last) is generally required for the completion of the manufacturing process of a semiconductor device. The challenge is to ensure the reliability of a gate dielectric layer (IL) of a high-k/metal gate last process. As is well known, fluoride can improve the effect of negative bias temperature instability (negative bias temperature instability, NBTI) of PMOS devices and hot-carrier injection (HCI) effects of NMOS devices. However, since the high-k dielectric layer process requires the removal of dummy gate dielectric layer (also known as a dummy gate oxide layer) prior to forming the gate dielectric layer and the high-k dielectric layer, the challenge is thus finding a way to implant fluoride ions into the high-k dielectric layer of the device.
In the case of silicon oxynitride (SiON) as a gate oxide layer or high-k dielectric layer/metal gate first process, implantation of fluoride ions can be performed into a dummy dielectric layer and source/drain after the dummy dielectric layer (typically polysilicon) has been formed and before peak annealing of the source/drain of the device. The fluoride ions can be fluorine or fluorine-containing compounds such as boron trifluoride). After annealing of the source and drain, a strong chemical bond between Hf—F and Si—F interface can be formed. However, a large dose of implanted fluoride ions may damage the semiconductor substrate. Thus, high-k dielectric layer last technology requires a thermal budget that does not use high temperature annealing.
Thus, finding a way to manufacture a semiconductor device having a high-k dielectric layer using a low thermal budget to reduce the effects of large doping of fluoride ions is highly sought after.